Support strap for cathode-ray tube gun parts



y 1951 K. A. HOAGLAND EI'AL 2,562,236

SUPPORT STRAP FOR CATHODE-RAY TUBE GUN PARTS FiledJune 6, 1950 Fig. 5 a-4 5 nvvmvroas KENNETH A. HOAGLAND ATTORNEYS Patented July 31, 1951SUPPORT STRAP FOR CATHODE-RAY TUBE GUN PARTS Kenneth A. Hoagland,Newark, and Eric Pohle, Clifton, N. J., assignors to Allen B. Du MontLaboratories, Inc., Clifton, N. J., a corporation of DelawareApplication June 6, 1950, Serial No. 166,403

8 Claims. 1

This invention relates to cathode ray tubes and more particularly to asupport strap in the electron gun portion of cathode ray tubes.

In cathode ray tubes having an electrode or electrodes which must berotationally fixed with respect to a given axis, such as ion trap tubesof the type described in copending application, Serial No. 129,260, byKenneth A. Hoagland, assigned to the same assignee, one of the principalproblems is to devise a rigid electron gun structure. This problem iscomplicated by a number of factors, one of which, in tubes of the typementioned above, is the fact that the electrode to be supported operatesat a potential vastly different from that of the electrodes mounted inthe same structure and precautions must be taken, therefore. to preventcorona breakdown. Another factor is shipment which may causemisalignment of any but the most rigid structures. These problems arefurther complicated by the economic necessity of translating. the gunstructure design into, a set of simple, easily fabricated parts that maybe rapidly assembled.

Consequently one object of this invention is to provide an improvedcathode ray tube gun structure.

Other objects are to provide an easily assembled ion trap type cathoderay tube, and to provide an electrode support strap for an electron gunof a type that is easily fabricated and provide an easily assembledrigid structure, properly aligned, which will remain aligned for thelife of the tube.

Another object is to provide apparatus for mounting electrodes at anangle with respect to other electrodes of an electron gun.

Other objects will be apparent after a study of the specification anddrawings, "in whicih Figure 1 is a side elevational view of an electrongun structure embodying this invention and mounted in the neck of acathode ray tube; I

Figure 2 is a plan view of the gun structure of Figure 1; and Figures 3,4 and 5 are plan, end and side views showing details of the anodesupporting strap in accordance with the invention.

In Figure 1 an electron gun is shown located within the neck II of acathode ray tube and attached thereto by the lead in and support wiresI2. The electron gun comprises a thimble shaped control grid I3, adishshaped second grid I I, and a tubular anode I6 all secured to a pair ofinsulating support rods H. The tubular anode I6 having a portion bent toextend axially at an angle to the remaining body portion as shown, is

' -a body portion 28 and laterally extending end partially supported atone end by a centering device I8, known as a spider, having metal legswhich contact the side wall of the tube II, for mechanical support andelectrical contact to a conductive coating 20 on the wall of tube II.The anode I6 is secured to the support rods by means of a strap I9having constructional features which form the subject matter of thepresent invention. It is desirable that the anode I6 be supported by thestrap I9 at a point somewhere near the center of the anode. If the strapI9 were moved further forward toward the spider Hi, the rear end of theanode I6 would be able to move with respect to the second grid I4, thuscausing an undesired misalignment of the electron gun. On the otherhand. if the support strap I9 were moved back along the anode I6, thedistance between the strap I9 and the tab H, which holds the second gridI4 onto the rods II, would be decreased and the possibility of breakdownby excessive leakage along the surface of the rods II would beencountered. Placing the strap I9 approximately at the center of theanode I6 has the still further advantage that the rods [1 aresufliciently long to insure an accurate alignment in the manufacture ofthe electron gun'prior to the time that the gun is inserted into thetube" I I.

Figures 3, 4 and,5 illustrate in detail one embodiment of the mountingstrap I9 comprising portions which are turned back onto themselves toform the loops'32. The axes of the loops 32 are at the same acute anglewith respect to the .body portion 28 as the angle which the rear part'ofthe tubular anode I6 makes with the forward part. 'The laterallyextending flat portions '3I formed between the body portion 28 of thestrap and the loops'32 are reinforced in double thickness by the ends 4|of the strap when in the manufacturing process the rods H are insertedinto the loops 32 and the ends II are spot welded to the fiat portions3| as indicated by the crosses in Figure 2. A rib 33 is embossed on thestrap I9 transversely through the body portion 28 and fiat portions 3|for stiffening the strap.

Another raised rib 34 extends longitudinally along the body portion 28.This rib 34 allows clearance for the flange 23 where a two piece anodeis used as shown in Figure 2 and providesa certain resiliencycircumferentially to permit the semi-cylindrical portion 28 to conformto the tubular anode I6 relieving strain in mass production particularlyin welding.

The strap I9 in Figure 4 may be a complete,

3 one piece unit, readily adaptable to methods of mass production. Thegaps between the flat portions 3| and the ends H are preferably closedby pressure and spot welded to grip firmly the support rods 11, when theelectron gun is being assembled. The strap I9 ed to the anode It asshown in Figures 1 and 2, Although this invention has been illustratedby specific examples, it will be obvious to those skilled in the artthat modifications may be made without departing from the scope thereof.

What is claimed is: 1. A supporting strap for a cathode ray guncomprising a central semi-cylindrical portion,

- lateral portions extending outwardly therefrom,

and cylindrical loop portions at the outer extremities of said lateralportions, the axes of said loop portions being parallel to one anotherand at an acute angle with the axis of said central portion.

2. A supporting strap for a cathode ray gun comprising a centralsemi-cylindrical portion, lateral portions extending outwardlytherefrom, and cylindrical loop portions at the outer extremities ofsaid lateral portions, the ends of said strap being extended from saidloops contiguous with said lateral portions, and secured thereto theaxes of said loop portions being parallel to one another and at an anglewith respect to the axis of said central portion.

3. A supporting strap for a cathode ray gun comprising a centralsemi-cylindrical body portion having an outwardly extendinglongitudinally disposed rib formed therein, lateral portions extendingoutwardly from said body portion, and cylindrical loop portions at theouter extremities of said lateral portions the axes of said loopportions being parallel to one another and at an angle with respect tothe axisof said central portion.

4. A supporting strap for a cathode ray gun comprising a centralsemi-cylindrical portion, lateral portions extending outwardlytherefrom, and cylindrical loop portions at the outer extremities ofsaid lateral portions, a transverse rib formed in and extending throughsaid central and lateral portions from one to the other is preferablyspot weld- 6. In the gun structure for a cathode ray tube, alongitudinally bent tubular, anode having two portions respectively oneither side of the bend therein and a' supporting strap therefor, saidstrap comprising a semi-cylindrical portion secured to saidanode,'lateral portions extendin outwardly therefrom, and cylindricalloop portions at the extremities of said lateral portions, thelongitudinal axes of said loop portions being at an angle with respectto the longitudinal axis of one said portion and parallel to thelongitudinal axis of the other said portion of said anode.

7. In the gun structure for a cathode ray tube having a longitudinallybent cylindrical anode having two portions respectively on either sideof the bend therein, a supporting strap secured to said anode comprisinga central semi-cylindrical portion, lateral portions extending outwardlytherefrom, and cylindrical loop portions at the extremitiesv of saidlateral portions, supporting rods for said gun structure, said rodspassing through said loop portions and frictionally secured thereto, theaxes of said rods and said loop portions being at an angle with respectto the axisof one said portion and parallel to the longitudinal axis ofthe other said portion of said anode.

8. In combination with support rods for a cathode ray gun having alongitudinally bent tubular anode having two portions respectively oneither side of the bend therein, a supporting strap comprising a centralsemi-cylindrical porof said loop portions, said rib extending outwardlyfrom said central portions the axes of said loop portions being parallelto one another and at an angle with respect to the axis of said centralportion.

5. A supporting strap for a cathode ray gun comprising a centralsemi-cylindrical body portion having an outwardly extendinglongitudinally axially disposed rib formed therein, lateral portionsextending outwardly from said body portion, and cylindrical loopportions at the outer extremities of said lateral portions, a transverserib formed in and extending through said central and lateral portionsfrom one to the other of said loop portions, said rib extendingoutwardly from said central portion the axes of said loop portions beingparallel to one another and at an angle with respect central portion.

tion, lateral portions extending outwardly therefrom, and cylindricalloop portions at the outer extremities of said lateral portions, theends of said strap being extended around said rods, contiguously alongsaid lateral portions and secured thereto the axes of said rods and saidloop portions being parallel to the longitudinal axis of one saidportion and at an angle with respect to the longitudinal axis of theother said portion of said anode.

KENNETH A. HOAGLAND. ERIC POHLE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,211,613 Bowie Aug. 13, 19402,393,057 O'Larte et a1 Jan. 15, 1948 2,429,824 Koch et al. Oct. 28,1947 2,432,037 OLarte et al. I Dec. 2, 1947 2,436,264 OLarte et al Feb.1'7, 1948 2,436,265 Pohle Feb. 17, 1948 OTHER REFERENCES Negative-IonBlemish in a Cathode Ray Tube and Its Elimination, by R. M. Bowie,Proceedings of the Institute of Radio Engineers, vol. 36,

to the axis of said No. 12, December 1948. (pp. 1482-1486).

